Image Editor - C / C++ / MFC Discussion Boards

how to create a port

sarath_babu12-Oct-04 21:04

sarath_babu

12-Oct-04 21:04

how to create a lpr port in windows 2000 without user interface

ashees

CListBox AddString Question/Problem

otrcomm12-Oct-04 20:45

otrcomm

12-Oct-04 20:45

Hello,

I am testing Rob Grove's SQLite wrapper called CppSQLite posted here at CodeProject, but I am running it in a Dialog based application. (CppSQLite is a great wrapper for SQLite, by the way).

I have some code that is adding lines to a ListBox instead of 'cout'ing it, but it is behaving strangely. At least I think it is! The following is a section of my code:

<snip>
try
{
int i, fld;
time_t tmStart, tmEnd;
CppSQLiteDB db;

SQLResultsStr.Format(_T("SQLite Version: %s"),db.SQLiteVersion());
m_List_Sqlite_Results.AddString(SQLResultsStr);

remove(gszFile);
db.open(gszFile);

SQLResultsStr = _T("Creating emp table...");
m_List_Sqlite_Results.AddString(SQLResultsStr);

db.execDML("create table emp(empno int, empname char(20));");

SQLResultsStr = _T("DML tests");

m_List_Sqlite_Results.AddString(SQLResultsStr);
<snip>

The problem is that no lines are added to the ListBox until the program completes execution. Then they all come flowing in at once!

The question is, why don't the m_List_Sqlite_Results.AddString(SQLResultsStr) statements add the string to the ListBox immediately after they are executed?

I hope this is clear!

Thanks,
Murrah Boswell

Re: CListBox AddString Question/Problem

Antony M Kancidrowski13-Oct-04 2:22

Antony M Kancidrowski

13-Oct-04 2:22

CListBox uses messages to add strings to the list. It may be that the paint messages are not being processed if your application is busy doing something like adding more entries within a tight loop.

You could force the update of the list control after each add with RedrawWindow(), that may have the desired effect.

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

Re: CListBox AddString Question/Problem

otrcomm13-Oct-04 5:15

otrcomm

13-Oct-04 5:15

Hello,

Thanks for the reply!

The statements are all executed sequentially. I.e., no loops.

Could it be that I turned off precompiled headers for one of my modules that is pure C++ code? This is the module that has all the SQLite database manipulation functions. I could not get the module to compile with precompiled headers, so I turned it off.

The RedrawWindow() command did work, but it does seem like additional overhead.

Thanks,
Murrah Boswell

Re: CListBox AddString Question/Problem

Antony M Kancidrowski13-Oct-04 8:51

Antony M Kancidrowski

13-Oct-04 8:51

otrcomm wrote:
Could it be that I turned off precompiled headers

No, If you have sections of code that rarely change then it is advisable to turn on precompiled headers. Basically they speed up compilation as the compiler does not need to compile all code each time you compile. (You do need to compile it all at least once however!) It is not necessary to have precompiled headers turned on.

otrcomm wrote:
The RedrawWindow() command did work, but it does seem like additional overhead.

Basically what you are doing here is ensuring that the list is redrawn before the code continues to execute. If you do not do this then paint messages are normally processed when the code comes to a natural break.

You may also be able to ease the problem by running the SQL code in another thread (leaving the main thread to process the paint messages) the choice is yours.

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

Re: CListBox AddString Question/Problem

otrcomm13-Oct-04 11:20

otrcomm

13-Oct-04 11:20

Hello,

Thanks again!

Since I am just testing the CppSQLite code too understand it better, I don't mind the overhead of the RedrawWindow() command now. However, under production code, I will take your advice and create a separate thread for the SQL code.

Another question. When you reply to my messages, I see parts of my message included. What setting at CodeProject do you have turned on to include the message you are replying too? I just get a blank textbox to reply in.

Thanks,
Murrah Boswell

Re: CListBox AddString Question/Problem

Antony M Kancidrowski13-Oct-04 11:37

Antony M Kancidrowski

13-Oct-04 11:37

otrcomm wrote:
When you reply to my messages

If you look at the text you are replying to, just underneath it is a button "Quote Selected Text". If you highlight the text and press the button it quotes it in the text of the reply.

In this case I highlighted "When you reply to my messages" and pressed the button.

Ant.

I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Williams (Little Britain)

Image Editor

Vini Deep12-Oct-04 20:38

Vini Deep

12-Oct-04 20:38

Hi all,
Does anybody know how image editors are made.I dont mean the image manipulation part ,but the canvas like thing we see in ms paint on which we draw ,erase .draw lines etc....I dont think it is a dilog.It would rather be a window , a paint window but how do we maintain it.say loading am image to a window is simple and i prefer the IPicture and IStream way of the win32 sdk.Once the image is loaded ,i even managed to draw on it ,like using moveto and line functions from the gdi.But the real trouble is how would i store the image temporarily.Say i have the image read from the file into the IStream and enclosed by IPicture .I render this from the IPicture to the window.Now i draw some lines over the image.Technically the dc is modified.Now how would i extract this modified dc into a buffer and latter on store it to a file.One suitable way is to Create a compatible dc and bitmap make a snapshot of this window,but it is not good,the image is not clear .How would i go around this situation.

Please help.

Vini

Help Needed (Toolbar)

Avinash Gupta12-Oct-04 20:28

Avinash Gupta

12-Oct-04 20:28

Hi,
How can I make a toolbar having buttons, which toggles their state from pressed to un pressed and vice versa like the toolbar of MS Paints?

Re: Help Needed (Toolbar)

Cedric Moonen12-Oct-04 20:49

Cedric Moonen

12-Oct-04 20:49

Take a look at PressButton from CToolBarCtrl.

help needed....Creating a 3D graph at the end of execution...

Kiran Satish12-Oct-04 19:25

Kiran Satish

12-Oct-04 19:25

Hi,

I have a program which generates a 2D data and i want to plot it into a 3D surface Plot at the end of the execution of my program.

at present i am writing it into a text file and then i am importing it inot excel file to plot the 3D graph... i would like to have tht 3D graph to be viewed in my program itself....( my prorgam is a plain cpp file...and I am running it in VC++, i think i have to convert it into ActiveX file... but I am not familiar with it)

anyone plz help me on this....hhow to proceed

thanks in advance,

Suman

deleting double pointers

Majid Shahabfar12-Oct-04 19:23

Majid Shahabfar

12-Oct-04 19:23

struct GroupConstant<br />
{<br />
CString** grpConst;<br />
};<br />
<br />
GroupConstant** m_pGrpConst;<br />
<br />
m_pGrpConst = new GroupConstant*[200];<br />
for(BYTE i=0 ; i<200 ; i++)<br />
m_pGrpConst[i] = new GroupConstant[50];<br />
<br />
CString** pstr = new CString*[4];<br />
for(BYTE i=0 ; i<4 ; i++)<br />
pstr[i] = new CString[2];<br />
<br />
<br />
GroupConstant** ppTemp = m_pGrpConst;<br />
GroupConstant* pTemp = (*m_pGrpConst);<br />
<br />
for(i=0 ; i<200 ; i++)<br />
{<br />
for(BYTE j=0 ; j<50 ; j++)<br />
{<br />
(*m_pGrpConst)->grpConst = pstr;<br />
(*m_pGrpConst)++;<br />
}<br />
(*m_pGrpConst) = pTemp;<br />
}<br />
m_pGrpConst = ppTemp;<br />

I have two double pointers. one is a content of the structure and other is pointer to the structure.
I initiate these double pointers as you see in the code. but now I have a problem with deleting these pointes.
how can I delete the double pointer included with structure and double pointer points to structur.
Thank you in advance.

How to solve this Problem?

pubududilena12-Oct-04 18:34

pubududilena

12-Oct-04 18:34

hi all,
I have created MFC Program.But when I compilled it ,I got such a Error:-
"fatal error C1189: #error : include 'stdafx.h' before including this file for PCH"
Can anybody please tell me how to correct that Problem Frown | :(

??

Thanks in advance..

Re: How to solve this Problem?

Ryan Binns12-Oct-04 18:48

Ryan Binns

12-Oct-04 18:48

Put #include "stdafx.h" at the top of the .cpp file that causes the error.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Re: How to solve this Problem?

pubududilena12-Oct-04 19:06

pubududilena

12-Oct-04 19:06

hi,
yes ..it is already in the top of the .Cpp file.But the Problem is appearing yet.
------This is the header file :------------------
// rtcsample.h : main header file for the RTCSAMPLE application
//
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#ifndef __AFXWIN_H__
#error include 'stdafx.h' before including this file for PCH
#endif

#include "resource.h" // main symbols

class CRtcsampleApp : public CWinApp
{
public:
CRtcsampleApp();
public:
virtual BOOL InitInstance();
};

This the .Cpp file-------------------------------------------
// rtcsample.cpp : Defines the entry point for the application.
include "stdafx.h"
// WinMain
//
int APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
HRESULT hr;
UNREFERENCED_PAR
//extra code here
}

Can you tell me how to correct it?
OR
Is there a Problem in "stdafx.h" File?

Re: How to solve this Problem?

Michael Dunn12-Oct-04 20:19

Michael Dunn

12-Oct-04 20:19

See the FAQ: http://www.codeproject.com/cpp/cppforumfaq.asp#cl_nopch[^]

--Mike--
Personal stuff:: Ericahist | Homepage
Shareware stuff:: 1ClickPicGrabber | RightClick-Encrypt
CP stuff:: CP SearchBar v2.0.2 | C++ Forum FAQ
----
Wizard needs food, badly!

How to put a progress in my project ?

King of Merit12-Oct-04 16:57

King of Merit

12-Oct-04 16:57

Hi,
In my project, I want to upgrade my application (there is a class named CUpgradeApplication in my project) by retrieving a file from web. And when the file was loading, I want to put a download progress but I don't know how to do.
Please help me.
Thank you very much.

Re: How to put a progress in my project ?

Sujan Christo12-Oct-04 18:19

Sujan Christo

12-Oct-04 18:19

Hi,
Have a look @ this article http://www.codeguru.com/Cpp/I-N/internet/filetransfer/article.php/c6235/[^]
Sujan

Re: How to put a progress in my project ?

ThatsAlok12-Oct-04 18:45

ThatsAlok

12-Oct-04 18:45

see The api UrlFiletoDownload or see article by mr Micheal Dunn in internet section overe this api

-----------------------------
"I Think It Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk

What does "const vector& vars" mean?

Rafferty Uy12-Oct-04 16:11

Rafferty Uy

12-Oct-04 16:11

Hello there,

I have been tracing a C++ code and I encountered a declaration statement like this:

const vector<int>& vars

Can anyone teach me what this is and how it is used? Smile | :)

I tried searching for references on this and I was not able to find any.

Thanks so much!

-Rafferty

Re: What does "const vector& vars" mean?

Ryan Binns12-Oct-04 18:07

Ryan Binns

12-Oct-04 18:07

Rafferty Uy wrote:
const vector<int>& vars

This is a reference to a constant template vector class that has been specialised with int as its template parameter, ie. it's a reference to a constant variable-length array of ints.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Re: What does "const vector& vars" mean?

Rafferty Uy12-Oct-04 20:41

Rafferty Uy

12-Oct-04 20:41

I see... could you give me an example on how to use this? or even a link to a reference will do. Sorry I really don't have an idea of this yet. I don't even know what a template in C++ is. Smile | :)

Thanks!

Rafferty

Re: What does "const vector& vars" mean?

Ryan Binns13-Oct-04 1:59

Ryan Binns

13-Oct-04 1:59

I don't know of any tutorials off the top of my head. I recommend you get a good C++ book that includes a section on templates, or google for a C++ template tutorial (or both Wink | ;)

)

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

File access rights

Anonymous12-Oct-04 16:04

Anonymous

12-Oct-04 16:04

Hi,

Can I rename/delete a file another process has open?

Thank you,

Re: File access rights

Ryan Binns12-Oct-04 18:12

Ryan Binns

12-Oct-04 18:12

Anonymous wrote:
Can I rename/delete a file another process has open?

Simple answer: No

Complex answer: You can't while it's open. You can use MoveFileEx() to delay the rename/delete until the next reboot, and let Windows do it for you at startup.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.